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channel.c
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1 /*
2  * Copyright (c) 2009, Microsoft Corporation.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License along with
14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15  * Place - Suite 330, Boston, MA 02111-1307 USA.
16  *
17  * Authors:
18  * Haiyang Zhang <[email protected]>
19  * Hank Janssen <[email protected]>
20  */
21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22 
23 #include <linux/kernel.h>
24 #include <linux/sched.h>
25 #include <linux/wait.h>
26 #include <linux/mm.h>
27 #include <linux/slab.h>
28 #include <linux/module.h>
29 #include <linux/hyperv.h>
30 
31 #include "hyperv_vmbus.h"
32 
33 #define NUM_PAGES_SPANNED(addr, len) \
34 ((PAGE_ALIGN(addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT))
35 
36 /* Internal routines */
37 static int create_gpadl_header(
38  void *kbuffer, /* must be phys and virt contiguous */
39  u32 size, /* page-size multiple */
40  struct vmbus_channel_msginfo **msginfo,
41  u32 *messagecount);
42 static void vmbus_setevent(struct vmbus_channel *channel);
43 
44 /*
45  * vmbus_setevent- Trigger an event notification on the specified
46  * channel.
47  */
48 static void vmbus_setevent(struct vmbus_channel *channel)
49 {
50  struct hv_monitor_page *monitorpage;
51 
52  if (channel->offermsg.monitor_allocated) {
53  /* Each u32 represents 32 channels */
54  sync_set_bit(channel->offermsg.child_relid & 31,
55  (unsigned long *) vmbus_connection.send_int_page +
56  (channel->offermsg.child_relid >> 5));
57 
58  monitorpage = vmbus_connection.monitor_pages;
59  monitorpage++; /* Get the child to parent monitor page */
60 
61  sync_set_bit(channel->monitor_bit,
62  (unsigned long *)&monitorpage->trigger_group
63  [channel->monitor_grp].pending);
64 
65  } else {
66  vmbus_set_event(channel->offermsg.child_relid);
67  }
68 }
69 
70 /*
71  * vmbus_get_debug_info -Retrieve various channel debug info
72  */
73 void vmbus_get_debug_info(struct vmbus_channel *channel,
74  struct vmbus_channel_debug_info *debuginfo)
75 {
76  struct hv_monitor_page *monitorpage;
77  u8 monitor_group = (u8)channel->offermsg.monitorid / 32;
78  u8 monitor_offset = (u8)channel->offermsg.monitorid % 32;
79 
80  debuginfo->relid = channel->offermsg.child_relid;
81  debuginfo->state = channel->state;
82  memcpy(&debuginfo->interfacetype,
83  &channel->offermsg.offer.if_type, sizeof(uuid_le));
84  memcpy(&debuginfo->interface_instance,
85  &channel->offermsg.offer.if_instance,
86  sizeof(uuid_le));
87 
88  monitorpage = (struct hv_monitor_page *)vmbus_connection.monitor_pages;
89 
90  debuginfo->monitorid = channel->offermsg.monitorid;
91 
92  debuginfo->servermonitor_pending =
93  monitorpage->trigger_group[monitor_group].pending;
94  debuginfo->servermonitor_latency =
95  monitorpage->latency[monitor_group][monitor_offset];
96  debuginfo->servermonitor_connectionid =
97  monitorpage->parameter[monitor_group]
98  [monitor_offset].connectionid.u.id;
99 
100  monitorpage++;
101 
102  debuginfo->clientmonitor_pending =
103  monitorpage->trigger_group[monitor_group].pending;
104  debuginfo->clientmonitor_latency =
105  monitorpage->latency[monitor_group][monitor_offset];
106  debuginfo->clientmonitor_connectionid =
107  monitorpage->parameter[monitor_group]
108  [monitor_offset].connectionid.u.id;
109 
110  hv_ringbuffer_get_debuginfo(&channel->inbound, &debuginfo->inbound);
111  hv_ringbuffer_get_debuginfo(&channel->outbound, &debuginfo->outbound);
112 }
113 
114 /*
115  * vmbus_open - Open the specified channel.
116  */
117 int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
118  u32 recv_ringbuffer_size, void *userdata, u32 userdatalen,
119  void (*onchannelcallback)(void *context), void *context)
120 {
121  struct vmbus_channel_open_channel *open_msg;
122  struct vmbus_channel_msginfo *open_info = NULL;
123  void *in, *out;
124  unsigned long flags;
125  int ret, t, err = 0;
126 
127  newchannel->onchannel_callback = onchannelcallback;
128  newchannel->channel_callback_context = context;
129 
130  /* Allocate the ring buffer */
131  out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
132  get_order(send_ringbuffer_size + recv_ringbuffer_size));
133 
134  if (!out)
135  return -ENOMEM;
136 
137 
138  in = (void *)((unsigned long)out + send_ringbuffer_size);
139 
140  newchannel->ringbuffer_pages = out;
141  newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
142  recv_ringbuffer_size) >> PAGE_SHIFT;
143 
144  ret = hv_ringbuffer_init(
145  &newchannel->outbound, out, send_ringbuffer_size);
146 
147  if (ret != 0) {
148  err = ret;
149  goto error0;
150  }
151 
152  ret = hv_ringbuffer_init(
153  &newchannel->inbound, in, recv_ringbuffer_size);
154  if (ret != 0) {
155  err = ret;
156  goto error0;
157  }
158 
159 
160  /* Establish the gpadl for the ring buffer */
161  newchannel->ringbuffer_gpadlhandle = 0;
162 
163  ret = vmbus_establish_gpadl(newchannel,
164  newchannel->outbound.ring_buffer,
165  send_ringbuffer_size +
166  recv_ringbuffer_size,
167  &newchannel->ringbuffer_gpadlhandle);
168 
169  if (ret != 0) {
170  err = ret;
171  goto error0;
172  }
173 
174  /* Create and init the channel open message */
175  open_info = kmalloc(sizeof(*open_info) +
176  sizeof(struct vmbus_channel_open_channel),
177  GFP_KERNEL);
178  if (!open_info) {
179  err = -ENOMEM;
180  goto error0;
181  }
182 
183  init_completion(&open_info->waitevent);
184 
185  open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
186  open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
187  open_msg->openid = newchannel->offermsg.child_relid;
188  open_msg->child_relid = newchannel->offermsg.child_relid;
189  open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
190  open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
191  PAGE_SHIFT;
192  open_msg->server_contextarea_gpadlhandle = 0;
193 
194  if (userdatalen > MAX_USER_DEFINED_BYTES) {
195  err = -EINVAL;
196  goto error0;
197  }
198 
199  if (userdatalen)
200  memcpy(open_msg->userdata, userdata, userdatalen);
201 
202  spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
203  list_add_tail(&open_info->msglistentry,
204  &vmbus_connection.chn_msg_list);
205  spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
206 
207  ret = vmbus_post_msg(open_msg,
208  sizeof(struct vmbus_channel_open_channel));
209 
210  if (ret != 0)
211  goto error1;
212 
213  t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
214  if (t == 0) {
215  err = -ETIMEDOUT;
216  goto error1;
217  }
218 
219 
220  if (open_info->response.open_result.status)
221  err = open_info->response.open_result.status;
222 
223  spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
224  list_del(&open_info->msglistentry);
225  spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
226 
227  kfree(open_info);
228  return err;
229 
230 error1:
231  spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
232  list_del(&open_info->msglistentry);
233  spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
234 
235 error0:
236  free_pages((unsigned long)out,
237  get_order(send_ringbuffer_size + recv_ringbuffer_size));
238  kfree(open_info);
239  return err;
240 }
241 EXPORT_SYMBOL_GPL(vmbus_open);
242 
243 /*
244  * create_gpadl_header - Creates a gpadl for the specified buffer
245  */
246 static int create_gpadl_header(void *kbuffer, u32 size,
247  struct vmbus_channel_msginfo **msginfo,
248  u32 *messagecount)
249 {
250  int i;
251  int pagecount;
252  unsigned long long pfn;
253  struct vmbus_channel_gpadl_header *gpadl_header;
254  struct vmbus_channel_gpadl_body *gpadl_body;
255  struct vmbus_channel_msginfo *msgheader;
256  struct vmbus_channel_msginfo *msgbody = NULL;
257  u32 msgsize;
258 
259  int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
260 
261  pagecount = size >> PAGE_SHIFT;
262  pfn = virt_to_phys(kbuffer) >> PAGE_SHIFT;
263 
264  /* do we need a gpadl body msg */
265  pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
266  sizeof(struct vmbus_channel_gpadl_header) -
267  sizeof(struct gpa_range);
268  pfncount = pfnsize / sizeof(u64);
269 
270  if (pagecount > pfncount) {
271  /* we need a gpadl body */
272  /* fill in the header */
273  msgsize = sizeof(struct vmbus_channel_msginfo) +
274  sizeof(struct vmbus_channel_gpadl_header) +
275  sizeof(struct gpa_range) + pfncount * sizeof(u64);
276  msgheader = kzalloc(msgsize, GFP_KERNEL);
277  if (!msgheader)
278  goto nomem;
279 
280  INIT_LIST_HEAD(&msgheader->submsglist);
281  msgheader->msgsize = msgsize;
282 
283  gpadl_header = (struct vmbus_channel_gpadl_header *)
284  msgheader->msg;
285  gpadl_header->rangecount = 1;
286  gpadl_header->range_buflen = sizeof(struct gpa_range) +
287  pagecount * sizeof(u64);
288  gpadl_header->range[0].byte_offset = 0;
289  gpadl_header->range[0].byte_count = size;
290  for (i = 0; i < pfncount; i++)
291  gpadl_header->range[0].pfn_array[i] = pfn+i;
292  *msginfo = msgheader;
293  *messagecount = 1;
294 
295  pfnsum = pfncount;
296  pfnleft = pagecount - pfncount;
297 
298  /* how many pfns can we fit */
299  pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
300  sizeof(struct vmbus_channel_gpadl_body);
301  pfncount = pfnsize / sizeof(u64);
302 
303  /* fill in the body */
304  while (pfnleft) {
305  if (pfnleft > pfncount)
306  pfncurr = pfncount;
307  else
308  pfncurr = pfnleft;
309 
310  msgsize = sizeof(struct vmbus_channel_msginfo) +
311  sizeof(struct vmbus_channel_gpadl_body) +
312  pfncurr * sizeof(u64);
313  msgbody = kzalloc(msgsize, GFP_KERNEL);
314 
315  if (!msgbody) {
316  struct vmbus_channel_msginfo *pos = NULL;
317  struct vmbus_channel_msginfo *tmp = NULL;
318  /*
319  * Free up all the allocated messages.
320  */
321  list_for_each_entry_safe(pos, tmp,
322  &msgheader->submsglist,
323  msglistentry) {
324 
325  list_del(&pos->msglistentry);
326  kfree(pos);
327  }
328 
329  goto nomem;
330  }
331 
332  msgbody->msgsize = msgsize;
333  (*messagecount)++;
334  gpadl_body =
335  (struct vmbus_channel_gpadl_body *)msgbody->msg;
336 
337  /*
338  * Gpadl is u32 and we are using a pointer which could
339  * be 64-bit
340  * This is governed by the guest/host protocol and
341  * so the hypervisor gurantees that this is ok.
342  */
343  for (i = 0; i < pfncurr; i++)
344  gpadl_body->pfn[i] = pfn + pfnsum + i;
345 
346  /* add to msg header */
347  list_add_tail(&msgbody->msglistentry,
348  &msgheader->submsglist);
349  pfnsum += pfncurr;
350  pfnleft -= pfncurr;
351  }
352  } else {
353  /* everything fits in a header */
354  msgsize = sizeof(struct vmbus_channel_msginfo) +
355  sizeof(struct vmbus_channel_gpadl_header) +
356  sizeof(struct gpa_range) + pagecount * sizeof(u64);
357  msgheader = kzalloc(msgsize, GFP_KERNEL);
358  if (msgheader == NULL)
359  goto nomem;
360  msgheader->msgsize = msgsize;
361 
362  gpadl_header = (struct vmbus_channel_gpadl_header *)
363  msgheader->msg;
364  gpadl_header->rangecount = 1;
365  gpadl_header->range_buflen = sizeof(struct gpa_range) +
366  pagecount * sizeof(u64);
367  gpadl_header->range[0].byte_offset = 0;
368  gpadl_header->range[0].byte_count = size;
369  for (i = 0; i < pagecount; i++)
370  gpadl_header->range[0].pfn_array[i] = pfn+i;
371 
372  *msginfo = msgheader;
373  *messagecount = 1;
374  }
375 
376  return 0;
377 nomem:
378  kfree(msgheader);
379  kfree(msgbody);
380  return -ENOMEM;
381 }
382 
383 /*
384  * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
385  *
386  * @channel: a channel
387  * @kbuffer: from kmalloc
388  * @size: page-size multiple
389  * @gpadl_handle: some funky thing
390  */
391 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
392  u32 size, u32 *gpadl_handle)
393 {
394  struct vmbus_channel_gpadl_header *gpadlmsg;
395  struct vmbus_channel_gpadl_body *gpadl_body;
396  struct vmbus_channel_msginfo *msginfo = NULL;
397  struct vmbus_channel_msginfo *submsginfo;
398  u32 msgcount;
399  struct list_head *curr;
400  u32 next_gpadl_handle;
401  unsigned long flags;
402  int ret = 0;
403  int t;
404 
405  next_gpadl_handle = atomic_read(&vmbus_connection.next_gpadl_handle);
406  atomic_inc(&vmbus_connection.next_gpadl_handle);
407 
408  ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
409  if (ret)
410  return ret;
411 
412  init_completion(&msginfo->waitevent);
413 
414  gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
415  gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
416  gpadlmsg->child_relid = channel->offermsg.child_relid;
417  gpadlmsg->gpadl = next_gpadl_handle;
418 
419 
420  spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
421  list_add_tail(&msginfo->msglistentry,
422  &vmbus_connection.chn_msg_list);
423 
424  spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
425 
426  ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
427  sizeof(*msginfo));
428  if (ret != 0)
429  goto cleanup;
430 
431  if (msgcount > 1) {
432  list_for_each(curr, &msginfo->submsglist) {
433 
434  submsginfo = (struct vmbus_channel_msginfo *)curr;
435  gpadl_body =
436  (struct vmbus_channel_gpadl_body *)submsginfo->msg;
437 
438  gpadl_body->header.msgtype =
439  CHANNELMSG_GPADL_BODY;
440  gpadl_body->gpadl = next_gpadl_handle;
441 
442  ret = vmbus_post_msg(gpadl_body,
443  submsginfo->msgsize -
444  sizeof(*submsginfo));
445  if (ret != 0)
446  goto cleanup;
447 
448  }
449  }
450  t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ);
451  BUG_ON(t == 0);
452 
453 
454  /* At this point, we received the gpadl created msg */
455  *gpadl_handle = gpadlmsg->gpadl;
456 
457 cleanup:
458  spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
459  list_del(&msginfo->msglistentry);
460  spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
461 
462  kfree(msginfo);
463  return ret;
464 }
465 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
466 
467 /*
468  * vmbus_teardown_gpadl -Teardown the specified GPADL handle
469  */
470 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
471 {
472  struct vmbus_channel_gpadl_teardown *msg;
473  struct vmbus_channel_msginfo *info;
474  unsigned long flags;
475  int ret, t;
476 
477  info = kmalloc(sizeof(*info) +
478  sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
479  if (!info)
480  return -ENOMEM;
481 
482  init_completion(&info->waitevent);
483 
484  msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
485 
486  msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
487  msg->child_relid = channel->offermsg.child_relid;
488  msg->gpadl = gpadl_handle;
489 
490  spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
491  list_add_tail(&info->msglistentry,
492  &vmbus_connection.chn_msg_list);
493  spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
494  ret = vmbus_post_msg(msg,
495  sizeof(struct vmbus_channel_gpadl_teardown));
496 
497  BUG_ON(ret != 0);
498  t = wait_for_completion_timeout(&info->waitevent, 5*HZ);
499  BUG_ON(t == 0);
500 
501  /* Received a torndown response */
502  spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
503  list_del(&info->msglistentry);
504  spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
505 
506  kfree(info);
507  return ret;
508 }
509 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
510 
511 /*
512  * vmbus_close - Close the specified channel
513  */
514 void vmbus_close(struct vmbus_channel *channel)
515 {
516  struct vmbus_channel_close_channel *msg;
517  int ret;
518  unsigned long flags;
519 
520  /* Stop callback and cancel the timer asap */
521  spin_lock_irqsave(&channel->inbound_lock, flags);
522  channel->onchannel_callback = NULL;
523  spin_unlock_irqrestore(&channel->inbound_lock, flags);
524 
525  /* Send a closing message */
526 
527  msg = &channel->close_msg.msg;
528 
529  msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
530  msg->child_relid = channel->offermsg.child_relid;
531 
532  ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
533 
534  BUG_ON(ret != 0);
535  /* Tear down the gpadl for the channel's ring buffer */
536  if (channel->ringbuffer_gpadlhandle)
537  vmbus_teardown_gpadl(channel,
538  channel->ringbuffer_gpadlhandle);
539 
540  /* Cleanup the ring buffers for this channel */
541  hv_ringbuffer_cleanup(&channel->outbound);
542  hv_ringbuffer_cleanup(&channel->inbound);
543 
544  free_pages((unsigned long)channel->ringbuffer_pages,
545  get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
546 
547 
548 }
549 EXPORT_SYMBOL_GPL(vmbus_close);
550 
565 int vmbus_sendpacket(struct vmbus_channel *channel, const void *buffer,
566  u32 bufferlen, u64 requestid,
567  enum vmbus_packet_type type, u32 flags)
568 {
569  struct vmpacket_descriptor desc;
570  u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
571  u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
572  struct scatterlist bufferlist[3];
573  u64 aligned_data = 0;
574  int ret;
575 
576 
577  /* Setup the descriptor */
578  desc.type = type; /* VmbusPacketTypeDataInBand; */
579  desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
580  /* in 8-bytes granularity */
581  desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
582  desc.len8 = (u16)(packetlen_aligned >> 3);
583  desc.trans_id = requestid;
584 
585  sg_init_table(bufferlist, 3);
586  sg_set_buf(&bufferlist[0], &desc, sizeof(struct vmpacket_descriptor));
587  sg_set_buf(&bufferlist[1], buffer, bufferlen);
588  sg_set_buf(&bufferlist[2], &aligned_data,
589  packetlen_aligned - packetlen);
590 
591  ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
592 
593  if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
594  vmbus_setevent(channel);
595 
596  return ret;
597 }
598 EXPORT_SYMBOL(vmbus_sendpacket);
599 
600 /*
601  * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
602  * packets using a GPADL Direct packet type.
603  */
604 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
605  struct hv_page_buffer pagebuffers[],
606  u32 pagecount, void *buffer, u32 bufferlen,
607  u64 requestid)
608 {
609  int ret;
610  int i;
611  struct vmbus_channel_packet_page_buffer desc;
612  u32 descsize;
613  u32 packetlen;
614  u32 packetlen_aligned;
615  struct scatterlist bufferlist[3];
616  u64 aligned_data = 0;
617 
618  if (pagecount > MAX_PAGE_BUFFER_COUNT)
619  return -EINVAL;
620 
621 
622  /*
623  * Adjust the size down since vmbus_channel_packet_page_buffer is the
624  * largest size we support
625  */
626  descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
627  ((MAX_PAGE_BUFFER_COUNT - pagecount) *
628  sizeof(struct hv_page_buffer));
629  packetlen = descsize + bufferlen;
630  packetlen_aligned = ALIGN(packetlen, sizeof(u64));
631 
632  /* Setup the descriptor */
633  desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
634  desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
635  desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
636  desc.length8 = (u16)(packetlen_aligned >> 3);
637  desc.transactionid = requestid;
638  desc.rangecount = pagecount;
639 
640  for (i = 0; i < pagecount; i++) {
641  desc.range[i].len = pagebuffers[i].len;
642  desc.range[i].offset = pagebuffers[i].offset;
643  desc.range[i].pfn = pagebuffers[i].pfn;
644  }
645 
646  sg_init_table(bufferlist, 3);
647  sg_set_buf(&bufferlist[0], &desc, descsize);
648  sg_set_buf(&bufferlist[1], buffer, bufferlen);
649  sg_set_buf(&bufferlist[2], &aligned_data,
650  packetlen_aligned - packetlen);
651 
652  ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
653 
654  if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
655  vmbus_setevent(channel);
656 
657  return ret;
658 }
659 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
660 
661 /*
662  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
663  * using a GPADL Direct packet type.
664  */
665 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
666  struct hv_multipage_buffer *multi_pagebuffer,
667  void *buffer, u32 bufferlen, u64 requestid)
668 {
669  int ret;
670  struct vmbus_channel_packet_multipage_buffer desc;
671  u32 descsize;
672  u32 packetlen;
673  u32 packetlen_aligned;
674  struct scatterlist bufferlist[3];
675  u64 aligned_data = 0;
676  u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
677  multi_pagebuffer->len);
678 
679 
680  if ((pfncount < 0) || (pfncount > MAX_MULTIPAGE_BUFFER_COUNT))
681  return -EINVAL;
682 
683  /*
684  * Adjust the size down since vmbus_channel_packet_multipage_buffer is
685  * the largest size we support
686  */
687  descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
688  ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
689  sizeof(u64));
690  packetlen = descsize + bufferlen;
691  packetlen_aligned = ALIGN(packetlen, sizeof(u64));
692 
693 
694  /* Setup the descriptor */
695  desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
696  desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
697  desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
698  desc.length8 = (u16)(packetlen_aligned >> 3);
699  desc.transactionid = requestid;
700  desc.rangecount = 1;
701 
702  desc.range.len = multi_pagebuffer->len;
703  desc.range.offset = multi_pagebuffer->offset;
704 
705  memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
706  pfncount * sizeof(u64));
707 
708  sg_init_table(bufferlist, 3);
709  sg_set_buf(&bufferlist[0], &desc, descsize);
710  sg_set_buf(&bufferlist[1], buffer, bufferlen);
711  sg_set_buf(&bufferlist[2], &aligned_data,
712  packetlen_aligned - packetlen);
713 
714  ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
715 
716  if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
717  vmbus_setevent(channel);
718 
719  return ret;
720 }
721 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
722 
736 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
737  u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
738 {
739  struct vmpacket_descriptor desc;
740  u32 packetlen;
741  u32 userlen;
742  int ret;
743 
744  *buffer_actual_len = 0;
745  *requestid = 0;
746 
747 
748  ret = hv_ringbuffer_peek(&channel->inbound, &desc,
749  sizeof(struct vmpacket_descriptor));
750  if (ret != 0)
751  return 0;
752 
753  packetlen = desc.len8 << 3;
754  userlen = packetlen - (desc.offset8 << 3);
755 
756  *buffer_actual_len = userlen;
757 
758  if (userlen > bufferlen) {
759 
760  pr_err("Buffer too small - got %d needs %d\n",
761  bufferlen, userlen);
762  return -ETOOSMALL;
763  }
764 
765  *requestid = desc.trans_id;
766 
767  /* Copy over the packet to the user buffer */
768  ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
769  (desc.offset8 << 3));
770 
771 
772  return 0;
773 }
774 EXPORT_SYMBOL(vmbus_recvpacket);
775 
776 /*
777  * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
778  */
779 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
780  u32 bufferlen, u32 *buffer_actual_len,
781  u64 *requestid)
782 {
783  struct vmpacket_descriptor desc;
784  u32 packetlen;
785  u32 userlen;
786  int ret;
787 
788  *buffer_actual_len = 0;
789  *requestid = 0;
790 
791 
792  ret = hv_ringbuffer_peek(&channel->inbound, &desc,
793  sizeof(struct vmpacket_descriptor));
794  if (ret != 0)
795  return 0;
796 
797 
798  packetlen = desc.len8 << 3;
799  userlen = packetlen - (desc.offset8 << 3);
800 
801  *buffer_actual_len = packetlen;
802 
803  if (packetlen > bufferlen) {
804  pr_err("Buffer too small - needed %d bytes but "
805  "got space for only %d bytes\n",
806  packetlen, bufferlen);
807  return -ENOBUFS;
808  }
809 
810  *requestid = desc.trans_id;
811 
812  /* Copy over the entire packet to the user buffer */
813  ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0);
814 
815  return 0;
816 }
817 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);
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